UAV data link has the characteristics of multi-service fusion,complex structure and dynamic reconfiguration,and the traditional reliability modeling methods cannot accurately represent its synchronization,concurrency,distribution,conflicts,resource sharing or competition.To solve the problem,a dynamic reliability modeling method of data link service based on GSPN is studied.The concepts of resource,repository and transition in GSPN model are used to describe various resources,states,behaviors and cooperative relationships in the data link system.The dynamic running process of the system is simulated by using specific random variables to represent the states and duration of the components.PIPE software tool is used for the formal modeling and description of the three major services of UAV data link,that is,uplink remote control,downlink remote measurement and downlink task payload transmission,so as to realize the accurate reliability evaluation.The case study shows that the proposed method can provide a trustworthy reliability evaluation method for UAV data link.